Imidazoline/alkylene oxide reaction products

ABSTRACT

A GASOLINE HAVING IMPROVED DETERGENCY AND ANTIICING PROPERTIES IS DESCRIBED. THE IMPROVED PROPERTIES ARE EFFECTED BY ADDING TO THE GASOLINE A SMALL BUT EFFECTIVE QUANTITY OF A NOVEL REACTION PRODUCT OF (A) 1-HYDROXYETHYL-2-ALKENYL IMIDAZOLINE AND (B) AN ALKYLENE OXIDE. THE NOVEL ADDITIVE AND THE METHOD OF PREPARING IT ARE ALSO DESCRIBED.

United States Patent O 3,560,520 IMIDAZOLINE/ALKYLENE OXIDE REACTIONPRODUCTS Warren L. Perilstein, Orchard Lake, Mich., assignor to EthylCorporation, New York, N.Y., a corporation of Virginia No Drawing.Original application Dec. 22, 1967, Ser. No. 692,706, now Patent No.3,449,095, dated June 10, 1969. Divided and this application Dec. 30,1968, Ser.

Int. Cl. C07d 49/30 US. Cl. 260-309.6 9 Claims ABSTRACT OF THEDISCLOSURE A gasoline having improved detergency and antiicingproperties is described. The improved properties are effected by addingto the gasoline a small but effective quantity of a novel reactionproduct of (a) 1-hydroxyethyl-2-alkenyl imidazoline and (b) an alkyleneoxide. The novel additive and the method of preparing it are alsodescribed.

CROSS REFERENCE TO RELATED APPLICATION This application is a division ofSN. 692,706, filed Dec. 22, 1967, now US. 3,449,095.

BACKGROUND OF THE INVENTION This invention is directed to gasolinescontaining additives which improve the detergency and antiicingcharacteristics of the gasoline, and the novel additives.

Gasolines used in internal combustion engines are known to causeundesirable deposits to form in the fuel system, for example, in thecarburetor. As these deposits build up, they tend to block gasoline andair passages thereby reducing the operating efficiency of the engine.

Additives are available for gasoline which reduce the accumulation ofthese deposits in the carburetor. These additives are commerciallyreferred to as carburetor detergents or gasoline detergents. The linearamino amide described in US. 2,839,373 is an example of a suitabledetergent.

It is apparent that the development of new gasoline detergents would bea contribution to the art. The invention described below is directed tosuch a discovery.

SUMMARY OF THE INVENTION A gasoline having improved detergency andantiicing properties containing a minor quantity of a product obtainedon reacting (a) a 1-hydroxyethyl-2-C -C -alkenyl imidazoline and (b) a CC alkylene oxide; the novel reaction product obtained on reacting (a)and (b).

A typical suitable reaction product is obtained by reacting l (2hydroxyethyl)2 heptadecenyl imidazoline with propylene oxide.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of this inventionis a gasoline containing a detergent quantity of a product obtained fromthe process which comprises reacting (a) an imidazoline having theformula r-e 11-0 H2 (OIIzM-OII wherein R is a hydrocarbon alkenyl grouphaving from 7 to about 19 carbon atoms, and (b) a lower alkylene oxidehaving the formula Ii -H C 0 H2 wherein R is seletced from hydrogen andalkyl groups having from 1 to about 6 carbon atoms, wherein the molarreaction ratio of the imidazoline to alkylene oxide is from about atleast 1:1 to about 1:2, at temperatures of from about C. to about 250 C.A preferred embodiment is the gasoline described above wherein R is analkenyl group having from 11 to about 17 carbon atoms. Another preferredembodiment is a gasoline as described above wherein R in Formula I has17 carbon atoms and R in Formula II is a methyl group. The gasolineconcentration of the product obtained from the reaction of compounds ofFormula I and the compounds of Formula II in these embodiments isgenerally from 5 to about 200 parts per million (p.p.m.) by weight with20 to about 70 p.p.m. by weight being preferred. A most preferredembodiment is the gasoline composition described above wherein thealkylene oxide is propylene oxide.

Another embodiment of this invention is the reaction product obtained onreacting the imidazoline having Formula I and a lower alkylene oxidehaving Formula II, as described above.

The reaction product which is used in the gasolines of the presentinvention is prepared by reacting an imidazoline having Formula I withan alkylene oxide having Formula II, at elevated temperatures. Ingeneral, the preparation is quite straightforward and amounts simply toadding the alkylene oxide to the imidazoline and then heating themixture, at the proper temperature for a sufficient period of time. Itis preferable to stir the mixture during the reaction.

The reaction is generally carried out at atmospheric pressure.

The imidazolines having Formula I which are useful in this invention arereadily obtained by reacting suitable organic acids withN-(Z-hydroxyethyl)ethylene diamine. This reaction involves theelimination of 2 molecules of water between the acid and the amine. Thisreaction is represented by the folowing equation:

In addition to the imidazoline, small amounts of a corresponding linearamino amide are also obtained. This amino amide is the result ofeliminating only one molecule of water between the acid and the amine.Methods of preparing the imidazolines are well known. Useful proceduresare described in Wilson, U.S. 2,267,965, and Wilkes, US. 2,214,152. Ascan be seen from the reaction equation given above, the R group in theimidazoline is the alkenyl residue of the particular acid which is usedin its preparation. In other words, the R group will have one carbonatom less than the acid which is used to prepare the imidazoline.

Acids which are useful in preparing the imidazolines are hydrocarbonmono-carboxylic acids having up to about 20 carbon atoms. The preferredacids are unsaturated organic acids are 9,10 decylenic acid, octenoicacid, oleic acid, linoleic acid, gadoleic acid and the like.

Preferred acids are commonly obtained as hydrolysis products of naturalmaterials. These acids thus obtained are mixtures. For example, acidsobtained from olive oil, typically are a mixture of about 83 percentoleic acid, 6 percent palmitic acid, 4 percent stearic acid and 7percent linoleic acid. This mixture is quite useful for preparingimidazolines to be used in this invention. Organic acid mixturesobtained on saponifying and acidulating babassu oil, castor oil, peanutoil, palm oil and the like, are examples of useful acids. A preferredimidazoline is 2-heptadecenyl-1- (2-hydroxyethyl)imidazoline.

A lower alkylene oxide having Formula II is the second reactant in theprocess for preparing the gasoline additive used in the presentinvention. Suitable alkylene oxides have up to about 8 carbon atoms.These alkylene oxides are the terminal oxides, that is, the oxideconfiguration is in the 1,2-position in the molecule. Examples of usefulalkylene oxides are 1,2-epoxy octane, 1,2-epoxy heptane, 1,2-epoxypentane and the like. Preferred alkylene oxides are the terminalalkylene oxides having up to about 4 carbon atoms. Examples of preferredalkylene oxides are 1,2-epoxybutane and ethylene oxide. A most preferredalkylene oxide is propylene oxide.

In preparing the reaction product of imidazolines having Formula I andalkylene oxides having Formula II, the molar ratio of the imidazoline toalkylene oxide is at least about 1:1. Molar ratios of imidazoline toalkylene oxide of from about 1:1 to about 1:2 can be used; a 1:1 molarratio is preferred.

The reaction between the imidazoline and alkylene oxide is generallycarried out at temperatures of from about 80 C. up to about 250 C. Thereaction is continued at this temperature until substantially all theimidazoline has reacted with the alkylene oxide. Generally, thisreaction will be substantially complete in from about to about 120minutes, higher reaction temperatures favoring a shorter reaction time.After substantially all the imidazoline has reacted with the alkyleneoxide, allowing the reaction mixture to stand for a longer time does notproduce any substantial change in the product. Thus, the reactionmixture may be kept for 2-20 hours or even longer before the reactionproduct is recovered without affecting the chemical nature of theproduct. The reaction product obtained within this range of temperaturesand times is substantially the same. In other words, the reaction may becarried out at 200 C. and be complete, that is, substantially all theimidazoline has reacted with the alkylene oxide, in 10 minutes; on theother hand, it will take a longer time, e.g. 3O minutes, to effect thesame reaction at temperatures of about 100 C. In any event the productobtained is substantially the same and is useful in the gasolines of thepresent invention.

In preparing the reaction product of the present invention, theimidazoline is generally heated to the desired reaction temperature andthen the alkylene oxide is added to it. If desired, a nitrogen blanketmay be used when heating the imadazoline. This tends to protect theimidazoline from hydrolysis especially, when high temperature orextended heating periods are used. However, the imidazoline may also beheated in air without affecting the nature of the reaction productobtained. It is also more convenient to heat the imidazoline in air.

Furthermore, the reaction with the alkylene oxide need not be carriedout under nitrogen. Therefore, the use of a nitrogen or other dry inertgas blanket is not essential in preparing the reaction products of thepresent position of matter having substantially little imidazolinestructure present. It is speculated that some cyclization may beoccuring which involves the alkylene oxide and the imidazoline molecule;however, this theory is not meant to limit the scope of the reactionproduct obtained.

The absence of the imidazoline function is the reaction product isdetermined by infrared analysis. Where the starting imidazoline has acharacteristic absorption band at 1550l600 cm. the infrared spectrum ofthe reaction product shows substantially no absorption in the 15501600cm. region. In the examples which will be presented below describing thepreparation of the reaction product, the product will be characterizedby stating that the infrared analysis indicated that the imidazoline hadreacted with the alkylene oxide; this means that the characteristicimidazoline infrared absorption band was substantially absent.

Following are examples illustrating preparations of the reaction productdisclosed above. All parts are by weight unless otherwise specified.

EXAMPLE 1 A vessel fitted with a nitrogen inlet, a thermometer and astirrer was charged with 85.5 parts (0.2 mole) ofZ-heptadecenyl-l(Z-hydroxyethyl)imidazoline and heated to 180 C. under astream of nitrogen. At this point a Dry Ice condenser was added to thesystem. The nitrogen flow was then discontinued and 11.7 parts (0.2mole) of propylene oxide was added to the imidazoline over a 35 minuteperiod, the temperature ranging from 180 to 192 C. The mixture was thenstirred for 30 minutes at 175 to 180 C. and was then allowed to coolunder an atmosphere of nitrogen. The product obtained was dissolved inbenzene and transferred to a second vessel. There the benzene wasremoved under reduced pressure on a steam bath. The product obtained was95.7 parts of a dark liquid. Infrared analysis indicated that theimidazoline had reacted with the propylene oxide. An elemental analysisof this product indicated total nitrogen was 6.5 percent, basic nitrogenwas 3.18 percent. The product had a base number of 123.1.

EXAMPLE 2 A vessel fitted as in Example 1 was charged with 85.5 parts ofthe Example 1 imidazoline and heated to 120 C. under nitrogen. To thisimidazoline was added 11.7 parts (0.2 mole) of propylene oxide was addedthrough the Dry Ice condenser over a 33 minute period, temperatureranging from 115 C. to about 120 C. The mixture was then stirred at thistemperature for thirty minutes. The product was recovered in a manneridentical with that used in Example 1. The product obtained was a darkliquid; the yield was 95.2 parts. Infrared analysis again indicated thatthe imidazoline had reacted with the propylene oxide'. Elementalanalysis of the product showed total nitrogen was 6.59 percent and basicnitrogen was 2.99 percent; base number was 120.6.

EXAMPLE 3 A vessel fitted as in Example 1 was charged with 85.5 parts ofthe imidazoline of Example 1 and heated to 120 C. under a constantnitrogen purge. The imidazoline was then cooled to 90 C. and 11.7 partsof propylene oxide was added over a 45 minute period at a temperatureranging from to C. The mixture was then stirred at this temperature for35 minutes and a product was recovered as in Example 1 above. The yieldof product was 91.4 parts of a dark fluid. Infrared analysis indicatedthat the imidazoline had reacted. Elemental analysis of the productshowed total nitrogen 6.77 percent, basic nitrogen 3.76 percent with abase number of 124.6.

EXAMPLE 4 A vessel fitted as in Example 1 was charged with 85.5 parts ofthe imidazoline of Example 1. The imidazoline was heated to 115 C. undera stream of nitrogen. The nitrogen flow was then stopped and 18 parts of1,2- butylene oxide was added to the imidazoline over a two hour period.The temperature during this addition period ranging from 115 to 120 C.The product was a brown fluid and the yield was 99.5 parts. Infraredanalysis showed that the imidazoline had reacted. Elemental analysisshowed the product had a base number of 112.8; total nitrogen of 6.33percent and basic nitrogen of 2.72 percent.

Similar results were obtained when 14.4 parts of butylene oxide wereadded to the imidazoline as in Example 4 over a period of 83 minutes.Analysis of the product thus obtained showed it had a base number of113.5, total nitrogen of 6.54 percent and basic nitrogen of 2.81percent.

EXAMPLE 5 A vessel fitted as in Example 1 was charged with 85.5 parts ofan imidazoline of Example 1; the imidazoline was heated to 115 C. undera stream of nitrogen. The flow of nitrogen was discontinued and about 11parts of ethylene oxide was slowly fed into the reaction vessel overabout a 45 minute period with a temperature ranging from about 116 toabout 121 C. The mixture was stirred for an additional hour at aboutthis temperature and it was then allowed to cool under nitrogen. Theproduct was recovered as in Example 1. The yield of a brown liquidproduct was 95.1 parts. Infrared analysis showed that the imidazolinehad reacted. Further analysis showed the product had a base number of117.4 with total nitrogen of 6.57 percent and basic nitrogen of 3.01percent.

Similar results were obtained when the charge of imidazoline of Example5 was 93.7 parts and the ethylene oxide added was about 12 parts. Theproduct obtained in this case was 103.7 parts of a brown fluid. Infraredanalysis showed that the imidazoline had reacted; further analysisshowed that the product had a base number of 133.2 with total nitrogenof 6.82 percent and basic nitrogen of 3.27 percent.

Other useful reaction products are prepared by reacting the followinglisted imidazolines and alkylene oxides substantially as described inExamples 1-5.

Any gasoline suitable for use in internal combustion engines may be usedin the practice of this invention. By gasoline is meant a blend ofhydrocarbons boiling from about 25 C. to about 225 C. which occurnaturally in petroleum and suitable hydrocarbons made by thermal orcatalytic cracking or reforming of petroleum hydrocarbons and mixturesthereof. Typical base gasolines are listed in Table 2.

TABLE 2.BASE GASOLINES A B C D Gravity, APT 59. 9 56. 6 62.0 39. 7 Reidvapor pressure, p.s.i. 9.0 11.2 10. 7 10.2 Sulfur, percent 013 007 054050 Percent armatics 27. 0 34. 19. 5 24. 0 Percent olefins 11.0 8. 0 18.5 12. 5 P ercent saturates. 62.0 57. 5 62. 5 63. 5 ASTM Distillation,

Initial B .P 100 89 90 88 evaporation 128 116 115 116 evaporation" 166177 155 165 evaporation 210 230 199 218 70% evaporation 250 282 254 27490% evaporatiom. 310 338 349 355 End Point 396 410 420 432 tit Theimproved gasoline compositions of the present invention can contain fromabout five parts per million (p.p.m.) by weight to about 200 p.p.m. byweight of said imidazoline/alkylene oxide reaction product.Concentrations of the imidazoline/alkylene oxide reaction productoutside this range may also be used if desired.

In preparing the improved gasoline compositions of the presentinvention, the imidazoline/alkylene oxide reaction product can be addedto the gasoline neat, that is, 100 percent active material, or as aconcentrate in a suitable solvent. Suitable solvents for these additiveconcentrates can be hydrocarbons such as toluene, xylene and the like,lower alcohols, and the like. Concentrations of the reaction productadditive in solution may range up to about 90 percent by weight. Use ofa solution containing the reaction product may facilitate additivemetering. In either case, conventional gasoline blend procedures andapparatus can be used in preparing the gasoline compositions.

The improved detergency characteristic of the gasoline compositions ofthis invention were determined using an actual engine test. The testinvolved measuring the amount of deposits formed on the carburetor of a6-cylinder automobile engine. The procedure involves running the engineat idle (500-700 rpm.) and no load for 20 hours, feeding blowby [1.0 cu.ft. per minute (c.f.m.)] and exhaust (0.5 c.f.m.) into the carburetorintake air. The air to fuel ratio is 8.0 and the fuel is fed from thepower jet only. The test is begun with a clean carburetor. At the end ofthe 20 hour test run, the carburetor is removed and the mg. of the totaldeposit formed in the carburetor (1) on a removable sleeve in thethrottle body and (2) on the throttle plate are determined. The weightof deposit is obtained by subtracting the weight of the clean carburetorsections (1) and (2) from the weight of the sections after the test. Theidle speed is used in the test since it is under this condition thatcarburetor formation is severe and adding blowby and exhausting to thecarburetor air, further accelerates deposit forma tion.

Data obtained in a series of experiments run according to the generalprocedure outlined above are presented in the following table. Theeffectiveness of the present additives is compared to a commercialadditive in this series of tests. All parts are by weight unlessotherwise indicated.

Base gasoline 1457-66 contains 22.0 percent aromatics, 62.5 percentsaturates and 15.5 percent olefinics.

2 Commercial detergent containing about percent active ingredient.

3 R11=Reaction product of 1 mole 2-l1eptadeeenyl-1-(2-hydr0xyethyl)imidazoline and 1 mole propylene oxide.

4 Rl 2=Reaetion product of 1 mole2-l1eptadeeenyl-1-(2-hydroxyethyDimidazoline and 2 moles propyleneoxide.

The data in Table 3 clearly illustrates the effectiveness of thereaction products herein described as carburetor detergents in gasoline.The gasoline without a detergent (Test 1) shows a carburetor depositbuild up of 136 mg. The reaction product of a heptadecenyl imidazolineand propylene oxide, in molar ratios of 1:1 (RP-1) and 1:2 (RP2) reducethe amount of carburetor deposit from 60 percent up to 88 percent byweight (com pare Test 1 with Tests 3, 5 and 7). In addition, the datashows that RP1 is comparable in effectiveness to commercial Detergent Aat 15 p.p.m. and superior to Detergent A at about 25 p.p.m.

Following is a list of gasoline compositions which are prepared usingthe base gasolines of Table 2 and the reaction products of Examples6-11. Each of these compositions has carburetor detergency effectivenesscomparable to that shown by the gasolines in Table 2, Tests 3, and 7.

TABLE 4.GASOLINE COMPOSITIONS Additive Additive concentraof exampletion, ppm.

Base gasoline Fuel composition:

In addition to carburetor detergency, the novel reaction products arealso effective antiicing additives in gasoline.

The gasoline compositions of the present invention may contain othergasoline additives such as, for example, antiknock compounds(tetraethyllead, tetramethyllead, methylcyclopentadienyl manganesetricarbonyl and the like); scavengers (ethylene dibromide,ethylenedichloride and the like); phosphate deposit modifiers (cresyldiphenyl phosphate, trimethyl phosphate and the like); metaldeactivators such as N,N-disalicylidine-1,2-diamino propane;antioxidants (alkylated phenols, phenylene diamine derivatives and thelike); lead appreciators (tert-butylacetate and the like); corrosioninhibitors, dyes and the like.

What is claimed is:

1. A reaction product obtained from the process which consistsessentially of reacting (a) an imidazoline having the formula wherein Ris hydrocarbon alkenyl of from 7 to 19 car- 8, bon atoms, and (b) alower alkylene oxide having the formula wherein R is selected fromhydrogen and hydrocarbon alkyl groups of from 1 to 6 carbon atoms, atmolar reaction ratios of (a) to (b) of from at least about 1:1 to about1:2, at atmospheric pressure and at temperatures of from about 80 C. toabout 250 C., said reaction product being characterized by having aninfrared spectrum showing substantially no absorption band at 1550 1600cm. said absorption band being characteristic of the imidazoline ring.

2. A reaction product of claim 1 wherein R has 17 carbon atoms, R ismethyl and said molar ratio of imidazoline to alkylene oxide is about1:1.

3. A reaction product of claim 1 wherein R has from 12 to 18 carbonatoms.

4. A reaction product of claim 1 wherein R is selected from hydrogen,methyl, and ethyl.

5. A reaction product of claim 4 wherein said molar ratio is about 1: 1.

6. A reaction product of claim 1 wherein R has 17 carbon atoms.

7. A reaction product of claim 6 wherein said molar ratio is about 1:1.

8. A reaction product of claim 7 wherein R is hydrogen.

9. A reaction product of claim 7 wherein R is ethyl.

References Cited UNITED STATES PATENTS 2,211,001 8/1940 Chwala 260-30962,987,514 6/1961 Huches et a1. 260-3096 3,056,688 10/1962 Olney 260-30963,231,580 1/1966 Mannhei-mer 260-3096 NATALIE TROUSOF, Primary ExaminerU.S. Cl. X.R. 44-63; 260-307 P UNITED STATES PATENT OFFICE (9)CERTIFICATE OF CORRECTION Patent No. 5, 5 0, 520 Dated February 2, 1971Inventorcl) Warren L. Perilstein It is certified that error appears inthe above-identified patent end that said Letters Patent are herebycorrected as shown below:

In Column 4, line 7, 'is" should be in In Column 5 line 69, "19.5 shouldbe 19.0 In Column 6, line 55, "58" should be 56 Signed and sealed this11th day of May 1971.

(SEAL) Attest:

EDWARD M.FIETGHER,JR. WILLIAM E. SCHUYLER,JR Attesting OfficerCommissioner of Patent

